Electrically programmable fuses (eFuses) used in re-routing circuits often include poly-silicon strips with a thin layer of silicide covering the top of the strips. eFuses, have become very popular recently, because of the circuit and systems design flexibility that it provides; the eFuse can be programmed even when the chip is mounted in the package and installed in the system. For example, customers can tailor a design to the specific needs of the application after the product is installed in the field. The eFuse also enables the freedom to alter the design, or fix any problem that may occur during the life of the product.
Passing current through the eFuse results in the electromigration of silicide material in the eFuse. Electromigration refers to the transport of material caused by the gradual movement of the ions in a conductor due to the momentum transfer between conducting electrons and diffusing metal atoms. As the trend of miniaturization in semiconductors continues, the reliability of prior art eFuses may suffer. Therefore, it is desirable to have an improved eFuse that offers reliable operation as the technology size continues to decrease.